Medical endoscopes having an elongated insertion tube for insertion into a body cavity for observing, treating and for performing medical procedures on organs, such as, bladders, kidneys, intestines, and the like, of the human body are extensively used in the medical field. Such medical endoscopes usually include an illumination source at or near the tip or leading end of the insertion tube, optical means for view in the illuminated area the organ and means for insertion through the tube and into the body cavity of a medical instrument for carrying out the intended medical procedure. Illumination is most often provided to the illumination source at the tip end of the tube through an optical fiber bundle passing through the tube from the illuminating source at the leading end of the tube to the opposite tube end outside of the body cavity and a light source at the end of the optical fiber bundle outside of the body. Similarly, the optical viewing means at the tip end of the insertion tube which, most commonly, is a lens, is connected by an optical fiber bundle to a viewing means, which may be an eye-piece, a camera, a television receiver, or similar instrument connected to the opposite end of the insertion tube outside the body upon which the endoscope is used.
To facilitate insertion of the endoscope tube and the direction of the tube tip to the internal area or areas to be illuminated and observed and, where desired, medical procedures are to be performed, medical endoscopes are commonly provided at or immediately behind the leading end of the insertable tube with a tube section which can be curved or deflected by manipulation from the opposite end of the endoscope tube which remains outside of the body. Thus, for example, by turning a knob, crank or handle, at the opposite end of the insertion tube, the leading end portion of the tube can be curved or deflected. The following or remaining portion of the tube is flexible. While not being manipulated with a knob, crank, handle or other means outside the opposite tube end, as is possible with the leading end, nevertheless, the following or remaining tube portion can curve or deflect as conditions require. As the leading end is curved or deflected by manipulation of the knob, crank, handle or other means as the tube is being inserted, the flexible following tube portion follows the path set by the curved or deflected lead portion. The leading and following sections of the insertion tube are constructed to allow curving and deflecting without, of course, damage or impairment to the enclosed fiber optics and other units.
In addition to medical uses, endoscopes or fiberscopes have found uses for industrial purposes, such as the inspection of parts and surfaces in areas where viewing and inspection is otherwise restricted. Thus, industrial fiberscopes are used for the inspection of internal parts or cavities of turbines, engines, motors, boilers, pipe lines and a wide variety of other units where access can be obtained for the tip end of the tube and the tip end can be controlled or manipulated, such as by a knob, crank, handle, etc., from the opposite tube end to guide or lead the tip end through the access opening and passage to the area to be observed. In an industrial environment, such as a turbine, engine, motor boiler, etc., surfaces which may be encountered by the outer walls of the insertion tube, as the tube is being inserted into or withdrawn from the cavity and opening or, in use, may be and usually are rough, sharp and abrasive. This leads to wear and damage to the surface or outer walls of the insertion tube. To protect the outer wall of industrial endoscopes it is usual practice to cover the peripheral surface with a protective cover of knitted or woven fine metal wire. The protective cover is applied so as to be replacable. However, such prior covers have been continuous, that is formed of a single unit extending from the leading or tip end of the tube to the opposite end. Thus, if damage to the cover occurs at the curvable leading section, the entire length of the cover must be replaced, even though, in the following section, the cover is undamaged. This, of course, increases labor and costs.